Air conditioning apparatus



, Junes, 1939. MQTERRY V 2,161,438

NNNNNN O R June 6, 1939. M, c. TERRY 2,161,438

AIR CONDITIONING APPARA' PUS Filed April- 6, 1957 4 Sheets-Sheet 2 k ML Y I 1 :SEE-E BY; /f I 5 f/ ,Q ATTNEY June 6, 1939. I M C, TERRY 2,161,438

' AIR CONDITIONING APPARATUS Filed April 6, 1937 4 Sheets-Sheet 3 INVENTOR I /lflmsa/VC 72,60/

fa,, TT NEY M. c. TERRY 2,161,438

AIR GONDITIONING APPARATUS Filed April 6, 1937 4 Sheets-Sheet 4 @x @Q @Q bm. m o w mu Q nm,

N x, lNvEN-roR /WfiTJa/VC Ekky BY 14,' ATT RNEY June 6, 1939.

Patented June 6, 1939 AUNITED -sTATEs PATEN-'I' OFFICE I 2,161,438 AIR CONDITIONING -APPARATUS Application April 6, 1937, Serial No. 135,271

11 claims. (ci 257-138) My invention relates to air conditioning apparatus, and more particularly to the type which is adapted to be installed in a room space and which operates lto condition the air in such room space.

My invention has for its general purpose or object to produce apparatus of the above type which is of improved construction and arrangement of parts.

A further object of my invention is to provide' apparatus of the above type which is simple in construction and is highly compact, and which supplies additional moisture to the air in the room space in an effective and efllcient manner.

The invention consists in the novel construction and combination of parts, to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specification, I .have fully and' clearly illustrated a preferred embodiment of my invention, in which drawings- Fig. 1 is a perspective view showing one prelferred embodiment of my invention.

Fig. 2 is a longitudinal vertical section of the apparatus shown in Fig. 1, the section being taken on the line 2.-2 of Fig. 3.

Fig. 3 is a ltransverse vertical section taken on the line 3-3 of Fig. 2. y

Fig. 4' is a transverse vertical section taken on the line 4-4 of Fig. 3.

Fig. 5 is an enlarged fragmentary vertical section` showing the humidifying conduit, the plane of the section being substantially the same as Fig. 2.

Fig. 6 is an enlarged fragmentary vertical secspace, and is operable to condition the air in said space.

The unit lil comprises an enclosing casing structure Which is divided interiorly by spaced vertical partition walls ll and |2 into a main or central compartment or section l3 and a pair of wing compartments or sections I4 and |5 located, respectively, at the sides of the main or central section. The unit IO also comprises a skirt portio'n IG surrounding the lower part of the V sides and front of the central section and the wing sections. 6 The central section l3 comprises a front wall l'i,

a top wall l8, a rear wall IS, and a bottom wall Zil.

Each'of the wing sections I4 and l5 comprises a bottom wall 2l, a top wallf22, a front wall 23, a rear wall 24 and an end wall 25. The partition 10 walls H and l2 serve as end walls for the main' section l3 and as end walls of the wing sections I 4 and l5.

In order to facilitate assembly of the unit IU and repair and replacement of the interior working parts,`the front wall 23, rear wall 24, top wall 22 and end wall 25 of each of the wing sections |4 and |5 areformed as a rigid unit which is detachably connected to the ends of the unit |3 by means of suitable bolts 30, 3! and 32, the bolts 30 serving to secure the front wall 23 to the bottom wall 2I, the bolts 3| securing the end wall 25 to the bottom wall 2l, and the bolts 32 securing the top wall 22 to the adjacent partition walls H' and l2. 25

The central section I 3 is provided. in its top wall IB with an inlet. opening 35 which communicates with the room, and is provided with a second inlet opening .36 in the upper rear part thereof -which is adapted to communicate with the outside atmosphere through a rearwardly extending horizontal duct 31. The duct 31 is adapted to extend between a window sill and the lower sash rail of a partially raised window (not shown). The duct 31 is detachably secured to 35 the central section by bolts 38 and 39. A damper 40 is arranged within the central section |3 and is pivoted at 4l and may be moved about its pivotal axis by a pull-rod 42 to proportion the amounts of room air and fresh air flowing into the central 40 section |3 through the inlet openings 35 and 36.

The top wall |8 of the central section i3 is also provided with an outlet opening 43 which communicates with the room space and is arranged adjacent and is of substantially the same size as 45 the inlet opening 35. The inlet opening 35 and outlet 43 are covered by suitable removable grills 44 and 45, respectively.

The interior of the main or central section is so constructed as to provide an upright U-shaped passage 46 (see Fig. 4) which includesa downcoming leg 41 connected at its upper end to the inlet openings 35 and 36, and an upgoing leg 48 connected at its upper end with the outlet opening 43. Arranged across the downcoming leg beneath the inlet openings 35 and 36 is a removable filter 50 which serves to remove from the air streamany solid particles in suspension therein; such, for example, as dust,, dirt, pollen,

etc.

Arranged immediately below the filter 50 and in the downcoming leg 41 is a cooling coil 5I consisting of a plurality of horizontally arranged pipes 52 connected by return bends 53, and a plurality of parallel iins 54 so arranged as to offer the minimum of resistance to the flow 'of air downward through the downcoming leg. A suitable liquid refrigerant is suppliedto the cooling coil through an inlet pipe 55, the latter being adapted to be connected to the discharge side of the conventional type of motor-compressor-condenser unit (not shown). The cooling coil is also provided with an outlet or discharge pipe 56 which may be connected to the suction side of such a motor-compressor-condenser unit.

Arranged in the bottom of the U-shaped passage and beneath the cooling coil 5l, is a condensate-collecting pan or receptacle 51 which is provided in its bottom with a drain connection 58 to which a discharge pipe 58 is connected, the latter being adapted to be connected tofla convenient drain pipe in the building (not shown). In Fig. 8 of the drawings, there is shown an alternative manner of removing the condensate from the receptacle 51a when the unit is not conveniently located with respect to a drain ,'pipe. In Fig. 8,,a pipe 59a connects at one end with the drain connection 58a and extends outward through the partition Ha and wing compartmentl4a, and the outlet end thereof is arranged to dischargethe condensate into a portable condensate receptacle 60 supported by the floor of the room and at the exterior of the unit.

Arranged in the lower part of the U-shaped passage 46 and at the'downstream side of the condensate-collecting pan 51, is a blower means 6l which operates to provide a positive flow of air from the inlets 35 and 36 through the passage 46 and through the outlet 43 into the room space. For this reason, the main or central section l3 may properly be termed an air circulating compartment. The blower means 6! here shown comprises an electric motor 62 having a shaft 63 which extends out bothV ends thereof. A pair of blower Wheels 64 are secured, respectively, to the two outerends of the motor shaft, and a pair of blower casings 65 surround, respectively, the blower Wheels 64. Each of the casings 65 is provided Vwith axial inlet openings or eyes 66 and with a vertical and radial discharge outlet 61, The motor, blower Wheels, and casing are secured as a unit to a supporting plate 68, and the latter is detachably supported at its ends by the partition walls H and l2, respectively.

The upgoing leg 48 is defined partially by the blower casings 65, and partially by a pair of vertically arranged duct sections 10. The duct sections are connected, respectively, at their lower ends to the discharge outlets 61 of the blower casings, and are connected at their upper ends to a duct portion 1l which extends longitudinally across the forward part of 'the central section i3 and communicates at its upper end with the outlet opening 43 (see also Fig. 2). duct sections 10 are small in cross-sectional area at their lower ends where they connect, respectively, with the casings 65, and their respective cross-sectional areas increase progressively from the casings 65 upward toward the section 1l.

The two duct sections 10 form a sound-dead- The' ened air passage which absorbs air and blower noises and thereby prevents such noises from being transmitted into the room. To this end, the sections 10 are lined with suitable soundabsorbing material indicated at 12, and slabs of this material extend transversely of the'sections to provide splitters 13 which perform the additional function of reducing eddy currents in the air stream and of directing the flow of the air upwardly into the section 1I.

Arranged above the upper ends of the two duct sections 10 and lengthwise of the section 1|, is a suitable heating coil 14, which is here shown to comprise a plurality of pipes 15 connected together at their ends, and a plurality of parallel fins 16 also fixed to the pipes and arranged in the same direction as the flow of air. Any suitable heating fluid, for example, steam or hot water, may be supplied to the inlet side' of the heating coil 14 by a pipe '11 in the wing section 15. A valve 18 sei ves to control the flow of heating fluid to the heating coil.

The apparatus so far described can be operated .to perform effectively the functions of circulating air within the room space, of introducing fresh outside air into the room, of filtering the room air and fresh air, of cooling and dehumidifying the air during the hot months of the year, and of heating the air .during the cold months of the year. The apparatus which performs these functions is highly compact, and is arranged within a casing structure of pleasing appearance. The apparatus is also capable of handling a relatively large amount of air for a given over-all size of unit. The cooling coil is advantageously positioned in the downstream leg 41 so as to facilitate the collection of Condensate. The spacing of the cooling and heating coils in the manner disclosed is advantageous from the viewpoint of safety, because if they should be placed adjacent one another, and both the heating and cooling coils placed in operation at the same time, the heat from the heating coil would cause such excessive pressures in the cooling coil as to endanger the latter and the connections thereto. The usual eddy currents at the downstream side o f a blower are eliminated by the splitters 13 and diverging ducts 10, and the air from the blower is therefore evenly distributed across the,lower part of the heating coil to provide uniform heating ofthe air and so that the latter will offer a minimum of resistance to the flow of air. The 'cooling coil will also offer a minimum of resistance to the flow of air as it is at the upstream side of the a blower.

In accordance With the present invention, I also provide an improved means for adding moisture to the air in the room space during the cold months of the year when artificial heat is required. To this end, I provide a humidifying conduit which is arranged for the most part in the wing section l4 and hasan open inlet end extending through an opening iii in the partition wall I i and into the upgoing leg'48 of the passage 46. The main body of the conduit 80 is arranged Within and extends upwardly through the wing section 14 and is connected at its open upper end with the room space through a humidified air outlet opening 82 in the top wall 22. The outlet opening 82 is arranged closely adjacent the end of the outlet opening 43 in the central section IS, for a purpose which Will presently appear.

The conduit 80 is here shown to be substantially L-shaped, with the short leg 84 of the L arranged horizontally and a part thereof extending into the passage 46, and with the 'long leg of the L arranged vertically in the section l4 and connected at its upper end with the room through the humidified air outlet 82.

The open inlet end of the leg 84 of the conduit is so constructed and arranged that a part of the air flowing from the blower will be diverted into the conduit and will flow positively through the conduit and into the room space. The inlet end of the conduit is preferably arranged at the downstream side of the blower instead of the upstream side, because the air pressure is greater at this point. The air pressure and velocity aid in providing the desired flow through the conduit 88'. The construction of the open inlet end of the leg 84 can be seen more clearly from an examination of Fig. 5. As shown, the outer free end of the leg 84 is cut vaway along a horizontal plane, as indicated at 86, and the extreme outer end of the upper or remaining part 8`| of the leg 84 is closed off by a suitable plate 88. This construction provides an inlet opening 89 vwhich faces downstream and `performs effectively the function of diverting a portion of the air stream into and through the conduit.

Arranged within the conduit 85 is a suitable means 98 for adding moisture to the air as it fiows therethrough. According to the broader as-` pects of my invention, this means may be of any desired type. -In accordance with the more specific aspects, I prefer that the means be of the type which discharges a fine mist or spray which may be more easily evaporated in the air. Tc this end, I provide a spray nozzle 9l which discharges a fine stream of water against an adjustable target '92 arranged thereabove. Water under pressure is supplied to the spray nozzle by means of a pipe 93. If desired, a suitable solenoid control valve 94 may be located in the pipe 83 for the purpose of controlling the operation of the spray from a remotely located switch or thermostat. A pressure-reducing valve 95 is also located in the pipe and serves to regulate the pressure of the water on the spray nozzle. Below the reducing valve is located a suitable strainer 88 for removing solid particles from the water to avoid clogging the spray head, and the lower end of the strainer may be connected to any suitable source. of water supply by means of a supply pipe 91. I

The spray Sl When operating will introduce water into the conduit 88 in an atomized form,. or mist. A portion of the mist will be evaporated in the air stream fiowing therethrough. Most of the remaining part of the mist will be entrained in the air stream and will be carried thereby into the room space through the humidified air outlet 82. As the outlet 82 is adjacent the outlet 43, 'and as the upper end of the upgoing leg 85 of the conduit 80 is in the form of a nozzle 88, andas this nozzle is inclined toward the air outlet opening 43, the entrained mist .or atomized water will be positively directed into the stream of heated air fiowing into the room space through the outlet 43; and, as a result, the mist 'will 'become quickly evaporated Vin the heated air. This type of construction and arrangement pro- 'vides for the addition of a relatively large amount ofl water into the atmosphere of a room spacev for a given size and capacity of air conditioning unit. Also, the air humidifying function is performed by apparatus which is relatively sr nall and'is compactly arranged in a small wing part of the air conditioning unit. This air humidifying 'in the top wall 22.

apparatus does not require a separate fan motor, as a. part of the main air stream is used for introducing the moisture into the room. A further advantage of the apparatus disclosed is that no moist air or fine water vapor is passed through the main part of the unit, thereby avoiding the troubles of deposit of solids on the heating coil, reduction in efficiency and .longevity of the acoustic material, and rusting and corrosion of parts contacted by the moisture.

A suitable drain connection ,l08 is provided in the bottom of the conduit 88 which serves to conduct away to the house drain excess water from the spray. In order to prevent the backflow of excess water from the spray intol the air passage 46, a dam in' the form of aplate IUI is arranged across the outer end of the lower part of the leg 84. The height of the plate is only sufiicient to perform this function without interfering with the flow of air into'the inlet end of the conduit. V

For the purposes of facilitating manufacture, assembly and repair, the conduit 88 is convenie'iit- 1y divideo into two detachable parts los' and uit; the 'lower part IOS being arranged partially .in the Wing compartment or section I'4 and partially in`the central compartment or section 1'8 and being detachably secured by screws -lfl'l to' the partition wall ll, and the` upper 'part IOS resting at its lower end on the part [86 and extending upwardly through the outlet opening 82 The spray nozzle 9! is detachably secured to the bottom wall of the' part I 06 by bolts' l08 passing through 'flanges' l88 forming a part of the drop elboW llll which is a part of the pipe 93. Thus,v by removing the bolts 38, 3! and 32, the unit formed by the top, front, rear and end walls of the wing compartment l4 may be quickly removed. The upper part IOS can then be lifted from the lower part IOS and any necessary repairs ean'be quickly made. If it is desired or'necessa'ry, the part IGG may then be quickly removed and the entire humidifying apparatus removed and the wing compartment l4 quickly reassembled. An advantage flowing from the readily detachable feature of this construction, is that it is not necessary for a customer to buy the humidifying part of the apparatus when he first buys the air conditioning unit, for the humidifying part can be quicklyand easily added after the unit l8 has been installed.

What I claim and desire to secure by Letters Patent of the United States is:

1. In air conditioning apparatus of the type,

adapted to be installed in a room space, the com- (with said first-named outlet; blower means in said passage providing for the'. positive flow' of air therethrough; a conduit arranged within said wing compartment and having an open outlet end communicating with said humidifled air outlet and having an open inlet end extending into said main compartment and said air passage at the downstream side of said blowerV and so ar-f -ranged with respect to the direction of air flow that a part of the stream of air flowing through the passage is diverted into the inletl end of said conduit and flows through said conduit and into.

the room through said humidified air outlet; and means in said conduit for adding moisture to the stream of air flowing therethrough.

2. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; partition means dividing said casing structure into a main compartment and a wing oompartment; said main compartment having an air outlet communicating with the room space and an air inlet spaced therefrom; said wing compartment having an outlet for humidified air and arranged adjacent said first-named outlet; means in said main compartment providing a passage for the flow of air connecting said inlet with said first-named outlet; blower means in said passage providing for the positive flow of air therethrough; means in said air passage at the downstream side of said blower for heating the air flowing therethrough; a conduit arranged within said Wing compartment and having an open outlet end communicating with said humidifled air outlet and having an open inlet end extending into said main compartment and said air passage at the downstream side of said blow- 'er and the upstream side of said heating means,

and the inlet end being so arranged with respect to the direction of air flow that a part of the stream of air owing through the passage is diverted into the inlet end of said conduit and flows through said conduit and into the room through said humidified air outlet; and means in said conduit providing a stream of atomized water or mist whereby the air flowing through the conduit entrains and carries such mist into the room space through said humidified air outlet.

3. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; upright partition means arranged in said casing structure and dividing the latter into a main compartment and a wing compartment; said main compartment having an air outlet in the upper part thereof communicating with the room space and having an air inlet spaced therefrom; means in said main compartment providing an air passage connecting said inlet opening with said outlet opening, with at least a part of said air passage extending upwardly through the compartment from the lower part thereof to the air outlet in the upper part thereof; blower means arranged in said passage and providing for the positive flow of air there-through; said wing compartment having a humidified air outlet in the upper part thereof; `an L-shaped conduit arranged within said wing compartment with the free end of one leg of the L extending through the partition means and into said main compartment and said upwardly extending portion of the air passage, and with the other leg of the L extending upwardly and connecting at its upper free end with the room space through the humidified air outlet; the free end of said one leg of the L having an opening therein so arranged with respect to the direction of air flow that it faces downstream, whereby air flowing through said passage is diverted into said conduit, and. such diverted part fiows through the conduit positively into the room .through the humidified air outlet; and means in the conduit for adding moisture to the air flowing therethrough.

4. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; upright partition means arranged in said casing structure and dividing the latter into a main compartment and a wing compartment; said main compartment having an air outlet in the upper part thereof communicating with the room space and having an air inlet spaced therefrom; means in said main compartment providing an air passage connecting said inlet opening with said outlet opening, with at least a part of said air passage extending upwardly through the compartment from the lower part thereof to the air outlet in the upper part thereof; blower means arranged in said passage and providing for the positive flow of air therethrough; said wing compartment having a humidified air outlet in the upper part thereof; an L-shaped conduit arranged within said wing compartment with the free end of on'e leg of the L extending through the partition means and into said main compartment and said upwardly extending portion of the air passage, and with the other leg of the L extending upwardly and connecting at its upper and free end with the room space through the humidified air outlet; the free end of said one leg of the L having an opening therein so arranged with respect to the direction of air flow that -it faces downstream, whereby air flowing through said passage is diverted into said conduit, and such diverted part flows through the conduit positively into the room through the humidified air outlet; water spray means arranged in said conduit for adding moisture to the air flowing therethrough; and means providing a dam across the lower part of said one leg of the L so as to prevent excess Water from said spray means from flowing through said one leg into the main compartment and air passage.

5. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; upright partition means arranged in said casing structure and dividing the latter into a main compartment and a wing compartment; said main compartment having an air outlet in the upper part thereof communicating with the room space and having an air inlet spaced therefrom; means in said main compartment providing an air passage connecting`said inlet opening With said outlet opening, with at least a part of said air passage extending upwardly through the compartment from the lower part thereof to the air outlet in the upper part thereof; blower means arranged in said passage and providing for the positive flow of air therethrough; said wing compartment having a humidifled air outlet in the upper part thereof; an L-shaped conduit having one leg thereof arranged substantially horizontal and extending through the partition means into the main compartment and upright part of the passage, and having its other leg arranged vertical and extending upwardly and through the humidified air outlet in the upper part of the wing compartment, the lower part of the free end of said horizontal leg being cut away to provide an inlet opening facing downstream with respect to the direction of flow of the air, and the upper part of said free end of the horizontal leg being closed at its extremity; and means for adding muciisture to the air flowing through said cond t.

6. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; upright partition means arranged in said ,casing structure and dividing the latter into a main compartment and a wing compartment; said main compartment having an air outlet in the upper part thereof communicating with the room space and having an air inlet spaced therefrom; means in said main compartment providing an air passage connecting said inlet opening with said outlet opening, with at least a part of said air passage extending upwardly through the compartment from the lower part thereof to the air outlet in the upper part thereof blower means arranged in said passage and providing for the positive fiow of air therethrough; said wing compartment having a humidified. air outlet in the upper part thereof; an L-shaped conduit arranged in said wing compartment and including a substantially horizontal leg extending through said partition and into said main compartment and the upwardly extending part of the air passage, and having a substantially vertical leg extending upwardly and connecting at its upper end with the humidified air outlet; the free end of said horizontal leg being cut away in the lower part thereof to provide an inlet opening facing downstream with respect to the direction of air flow; the extreme outer free end of the upper part of said horizontal leg being closed; the outer end of the lower part of said horizontal leg being closed to provide a dam; spray means arranged within said conduit; and means for draining away excess water from the horizontal leg of said conduit.

7. In air conditioning apparatus of the type adapted to be installed in a room space, the combination of wall means defining a casing structure; upright partition means `varranged at =one side of said casing' structure and dividing -the latter into a main compartment and a wing compartment; said main compartment having an air inlet in the upper part thereof and an air outlet in the upper art thereof communicating with the room space and spaced from the air inlet; means in said main compartment providing an upright U-shaped passage, including a downcoming leg connected at its upper end to said air inlet and an upgoing leg connected at its upper end to said air outlet; blower means arranged in said passage and providing for the positive fiow of air through said passage;

a heating coil arranged across the upper part of said upgoing leg; said wing conmpartment having a humidified air outlet in the upper part thereof adjacent saidrfirst-named airoutlet; a conduit arranged within said wing compartment and having an open outlet 'end connecting with the humidified air outlet, and having an open inlet end extending through said partition means and into the upgoing leg ofsaid passage between the blower and the heating coil, and the open inlet end being so arranged as to divert a part of the stream of air flowing through said passage into said conduit and into the room space through the humidified air outlet; and means in said conduit for adding moisture to the air as it flows therethrough.

8. In air conditioning apparatus for use in `room spaces, the combination of an enclosing casing having spaced inlet and outlet openings;

wall means in said casing providing a main air circulating and heating compartment connecting said inlet and outlet openings; a blower in said compartment providing for the positive flow of a stream of air therethrough from the inlet opening to the outlet opening and into the room; a heating device in the compartment and arranged across the air stream at the discharge side of the blower; and means for by-passing a portion of the air stream around the heating device and for humidifying such by-passed portlon; said means comprising ,a conduit having an open inlet end and an open outlet end and said conduit except for its inlet end beingarranged outside of said compartment and ex- Itending in the general direction of air fiow through said compartment, said open inlet end being arranged within said compartment between the discharge of the blower and said heating device, and facing generally in an up-stream direction so as to provide for the diversion of a portion of the air stream thereinto and for the positive flow of the diverted portion through said conduit, said open outlet end being arranged adjacent said casing outlet opening so that the diverted por-tion mixes with the main body of the air after the latter has passed over the heating device, and means for adding moisture to said diverted portion as it flows through said conduit.

9. In air conditioning apparatus for use in room spaces, the combination of a casing having spaced inlet and outlet openings; wall means in said casing providing a main air circulating and heating compartment connecting said inlet and said outlet .openings; a blower in said compartment providing for the positive fiow of air therethrough from the inlet to the outlet and into the room space; a heating device in said compartment and arranged across the air stream at the discharge side of the blower; and a unitary air-humidifying device structurally separate from said casing and compartment and operable to divert a portion of the air stream from said compartment ahead of said heating device, humidify such diverted portion and then mix the diverted and humidified portion with the main body of the air stream after the latter has passed over the heating device; said device comprising a conduit having an open inlet end and an open outlet end and so arranged that it extends in the general direction of flow of air through said compartment, the open inlet end being arranged within the compartment between the blower discharge and the heating device and facing generally in an up-stream direction, the open outlet end communicating witn the main air stream after the latter has passed over the heating device, and means in said conduit for adding moisture to the air fiowing therethrough.

10. In air conditioning apparatus for use in room spaces, the combination of a casing having partition means providing flrst and second compartments; said first compartment having spaced inlet and outlet openings; a blower in said first compartment providing a stream of air flowing therethrough from the inlet to the into and fiows posltively through the conduit; the conduit having an open outlet end arranged to discharge the diverted portion of the air stream into the main body of the air stream after the latter has passed over the heating device; and means in said conduit for adding moisture to said diverted portion as it flows through the conduit.

11. In air Conditioning apparatus for use in room Spaces, the combination of an enclosing casing having spaced inlet and outlet openings; wall means in said casing providing an air pas- Sage connecting said inlet and outlet openings; a blower in said casing providing for the flow of air through said passage from the inlet to the outlet and into the room space; a heating device arranged across the passage and in the path of 'the air stream at the discharge side of the blower; an L-shaped conduit separate from said passage and arranged within said casing with the free end of one leg extending laterally into said passage and with the other leg extending in the general direction of flow of the air stream and terminating at points beyond the heating device; the free end of said one leg being open and facing generally in an up-stream direction so as to provide for the diversion of a portion of the air stream thereinto and for the positive flow of such diverted portion through said condui-t; the free end of said other leg being open and so arranged that the diverted portion of the air stream mixes with the main body of the air stream after the latter has passed over the heating device; and means for adding moisture to said diverted portion as it fiows through said conduit.

MATSON C. TERRY. 

